Some Words about Reasonable Answers

1. An answer to any problem is an estimate. As such, you should not express the answer with greater precision than is warranted by the problem statement and means used to obtain the solution. A good rule of thumb is to use no more than 3 significant figures unless there is a good reason to do so. Where gross, ballpark-type estimates are used, limit the answer to 2 signficant figures.

Examples: bad: 2.81242329. good: 2.81, or even 2.8 if there is only 1 signficant figure of accuracy or precision.

2. Use the appropriate units. Generally accepted practice is to have 1, 2, or 3 signficant figures before the radix point. This usually means frequent use of K, M, G, T, m, etc. suffixes.

Example: bad: 2,123,000,000. Good, 2.13 Billion. Bad: .00000213 seconds. Good: 2.13 microseconds.

3. Wherever possible and reasonable, use dimensional analysis to check your answers.